Add a value_type typedef to SmallVector, to make it more compatible with STL adapters.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54819 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/SmallVector.h

@@ -90,6 +90,7 @@ public:
   }
   
   typedef size_t size_type;
+  typedef T value_type;
   typedef T* iterator;
   typedef const T* const_iterator;